Tilting chair



(No Model.)

J. WfKENNA.

- TI'LTING GHAIR.

Patented E LA, 11884.

1 n PETERS. mm m. \lluhinllom u. a

ilnrrnn STATES P rrnNr Grinch,

JOSEPH w. KENNA, or onrcheo inmnois.

TILTING CHAI R.

SPECIFICATION-forming part of Letters Patent No. 294,891, dated March 4,1884,

Application filed April 23, 1883. (No model.)

To all whom it may concerni Be it known that I, JOSEPH W'. KENNA, acitizen of the United States, residing at Ohicago, in the county of Cookand State of Illinois, have invented certain new and useful Improvementsin Tilting Chairs, of which the following is hereby declared to be-afull, clear,

, and exact description, sufficient to enable othspider; Fig. 5, aviewin detail of the tie-plateand retaining-bolt.

The nut or base-block a. consists of a hollow casting,having rectangularrecesses on its outer face,withinwhich'are set the feet a, the wholeconstituting a base-support for the chair. The feet are secured inposition by screw-bolts or the like passing through the flanged base aof nut a and through the Gap-plate a In process of making the nut a, thethreaded spindle b, with which it engages, is coated with linseed-oil ora slip of clay and dusted with graphiteor white lead, and so disposed inthe hollow nut a.

mold as to form both a core and a chillto the Hence it is that when thecast is made the threads on the nut a will be in ex.- aot counterpartwith those on spindle b, and

will be hardened by reason of the chill, so

that in this simple way a firm, even, and durable connection between nutand spindle is effected, which prevents the chair from becoming ricketyand loose. The long threaded spindle 12 carries the chair-seat andframe, and, being free to revolve within nut to, may be quickly raisedor lowered therein to adjust the chair to the comfort'of the occupant.

Rigidly secured to the top of spindle b is a cast-metal standard, 0,the'vertical projecting tongues c of which are tapered to an edge, andpreferably chilled or case-hardened, to enable them to better resistwear. The tongues c bear upon the spider dwithin suitable seats, as atd, adapted to receive said tongues, the seats being slightly cut away,so as to allow saidspider d a limited play or poise after the manner ofan ordinary balance about theedges of the tongues c as points ofsuspension. The

or case-hardened in process of making the d of the spider are secured attheir ends to the chair-seat frame in any suitable manner.- A verticalretaining-bolt, e, is freely set within an open-front recess in theupper part'of standard 0, there being shoulders c' at the sides of therecess, against which the head of the bolt e may abut. The bolt 6extends upwardly through a hole in spider d, and about its upper endcarries looselya tie-plate, f, the side wings of which are reduced to abearing-edge, and preferably chilled or case-hardened. The wings of theplate f bear against the depressed socket of spider d, within which theyrest.

By turning the set-nut e on the bolt 6 the spider d is forced down uponthe vertical tongues c of the standard 0, and as well the wings of theplate f are forced against the base of the depressed socket in spider d.

ing-edges or supports of tongues c are in alignment Withthe likesupports on the wings of tie-plate f. Hence it. is that spider d mayrock about the bearing-edges of tongues c as a pivot without wrenchingthe retaining-bolt e, which remains substantially vertical by reason ofthe poise or adjustment of the tie-plate f about its bearing-edges witheach change in tie-plate, said plate may be hemispherical in shapeandadapted to rest within a recess of spider 21, made with like contour;or, if desired, the tie-plate maybe entirely omitted, though in suchevent the shearing strain on the retaining-bolt is much increased andthe security of spider d in equipoise above standard a correspondinglylessened. The bearings for side wings of tie-plate f shouldbe suitablyhardened while casting spider d or otherwise, to enable them better toresist wear. Should the parts become loosened or rickety, it isnecessary merely to tighten up the setnut e. to insure firm and evenmovement of the spider about its bearing-edges on the standard. A rod,g,which may be permanently joined to standard 0 in casting or be securedthereto seats d for the tongues c are preferably chilled spider,toincrease their durability. The arms It will be noted from Fig; 4 thatthe bearposition of spider :d. In lieu of wings to the afterward,projects forward from said standard into and through an elongated slot,(1, in a dependent extension of spider d, and carries near its front enda sliding plate, 71, which is socketed to receive the ends ofrecoil-springs 17. The springs 17, at their opposite ends, rest againstthe ears (7 on the dependent extension of spider d, and there may bestuds 0'' 011 said ears d, to better retain the spring 2' in place. Ahand-wheel, I, threaded to redo, forces sliding plate It along said rod,so as to compress the springs 5 against the dependent extension ofthespider (l. The bearing-edges or points of oscillation between spider dand standard 0 are preferably located slightly back of the center ofgravity of the chair-seat, so thatin ordinary use the dependentextension of the spider will bear firmly against the upright portion ofstandard 0, and the chair-seat will rest steadily in horizontalposition. The tension ofsprings i also serves to keep the seat in place.\Vhen the chair is in use and the occupant shifts his position, so thatthe center of gravity is back of the points of oscillation, then thechair-seat and spider may tilt in even poise about the verticalbearing-edges c and against the tension of springs 1 giving an easyrocking move ment to the chair. The tilting of the chairscat is checkedby contact of the bottom of slot (1 with the rod r The elements ofstructure formed and united as herein described, being in the main ofcast metal and few in number, are easily and cheaply made, requirelittle or no fitting together if the molds are accurate, and when set upproduce an easy-moving and durable tilting chair which is less liable toget out of order than the more complicated forms heretofore in use.

By hardening all of the bearing parts or faces, as hercinbefore set out,theloosening or rickety condition of the chair consequent upon unevenwear is very much reduced.

It is to be noted that sliding plate 71. should preferably have anangular perforation corresponding with rod 5 so that while free to slideit may not turn thereon to disarrange the springs 2 In lieu of thedouble springs 1 which make the tilting movement of the chair moreequable, there may be more, or there may be merely a single springencompassing spindle g. It is plain that the knife-edge supports may betransferred to the spider and the bearings therefor to the standard,thus reversing .or making the knife-edge pivots the counterpart of whatis shown. These and all other like modifications are obviously withinthe range of the skilled mechanic to adopt, and equally within thespirit of the present invention.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In combination, the spindle, a standard fixed thereon, and providedwith knife-edge tongues extending in the same general direction with thespindle, and the spider recessed, substantially as described, to receivethe said tongues, whereby a vertical bearing-edge is produced for thechair-seat, substantiallyas set forth.

2. The combination, with the base-support, of the projecting spindle,the standard secured thereto and having vertical knife-edge tonguesextending therefrom, and the spider to which the chairseat is attached,said spider being suitably recessed to receive said tongues, substantially as set forth.

3. The combination, with the base-support, of the projecting spindle,the standard secured thereto and having vertical lniite-edgetongucsextending therefrom, the recessed spider to which the chair-seat isattached, and the retaining-bolt which holds said standard and spidertogether, substantially-as described.

4. The combination, with the basesupport, of the spindle, the standardsecured thereto and having vertical knife-edge tongues extendingtherefrom, the recessed spider, the retaining-bolt, and the tie-plateeo-operating therewith to hold said standard and spider in position,substantially as described.

5. The combination, with the base-support, of the projecting spindle I),the standard 0, secured thereto and having vertical bearingedges 0, therecessed spider d, the retainingbolt 6, and adjustable spring mechanism,substantially as described, co-operating with said standard and spiderto return thelatter to position when tilted about the verticalbearingedges, substantially as set forth.

(5. The combination, with the base-support, and with the projectingspindleb, of the standard c, secured thereto, the spider (I, providedwith a dependent portion, as described, and tilting about said standard,the rod g, extending from the standard and through the dependent portionof the spider, the sliding plate h and adjusting-wheel l, mounted onsaid rod, and the double recoil-springs 1?, retained between the slidingplate and the dependent extension of the spider, substantially as setforth.

In testimony whereof, witness my hand this 20th day ofApril, 1883.

J OSEPl-I XV. KENNA.

\Vitnesses:

G120. 1. FISHER, J r., OrmuLEs W. tASMUSEN.

IIO

